A 2019 study, led by Dr Thava Palanisami and other researchers at the University of Newcastle, Australia, and commissioned by the World Wildlife Fund for Nature, reported that humans are gobbling upto 5 grams of microplastics in their weekly diets — or about as much as the weight of an ATM card. Recognised globally by the United Nations Environment Programme (UNEP) as a world-leader in microplastics research, Dr Palanisami's expertise earned him an invitation to speak at the Geneva Beat Plastic Pollution Dialogues in 2021. Ahead of the World Environment Day 2023, with its crucial theme of ‘Beat Plastic Pollution’, Dr Palanisami, in an exclusive interview with LetMeBreathe, delves deep into the intricate complexities surrounding microplastics.

Edited excerpts from the interview: 

Share Briefly About The Work That You Are Doing On Plastics? 

So the work that I'm doing is looking at the risk assessment of environmental and human health effects of plastics and its related chemicals. Mainly, we focus on occurrence and distribution of plastics in the soil, air, water, and then how it actually enters our food chain, and what kind of effects it can cause. And in that, we worked out the world's first concentrations of plastic exposure to humans. And that would set a benchmark for the UN Plastic Treaty that was being discussed in France recently. And so, because previously there was scattered information, there was no uniform methodology to understand how much plastic we are exposed to. So we brought that for the first time in 2018. In addition to that, we also work on treatment technologies and plastic alternate products. So, it is like a pilot to build the scale and commercialise technologies to manage plastic pollution.

Your 2019 Study Reported How Humans Are Ingesting Alarming Amounts Of Plastics. So Have We Understood The Gravity Of The Situation And Are We Working Towards It?

In the study, we reported that up to five grams of plastic is the highest amount being ingested by humans. We understand the gravity of the problem, and that was the reason I was invited to talk in the Geneva Environmental Network and National Academy of Science, USA. It was to present the seriousness of this issue, and also the UN rightly captured it in the Plastic Treaty. So, that itself indicates the gravity of the issue, otherwise the UN would not have been involved in it.

How Does Microplastics Affect Our Biodiversity?

Microplastics mainly come through water, food sources and the air we breathe. There are two types – primary microplastics and secondary microplastics. Primary particles are large like bottles, they break down, get converted to microplastics and then these enter the environment and go to our food chain like fish and other food products and then eventually enter our bodies. Secondary microplastics are small-sized plastic particles produced intentionally. In terms of the effect, the environmental effect is well understood as to how it affects the soil, water ecosystem and marine life. Plastic-related chemicals can leach into the body and it can block the gut. It can also carry pathogens. In humans, the evidence and research on the exact risks is still being assessed. So there are studies finding microplastics in blood and urine. However, plastics are known to contain hundreds of toxic chemicals, and a continuous exposure may result in the same relationship like endocrine disrupting chemicals, which have already been established to cause harm to our endocrine system. And so, in a similar manner, plastics which contain a high amount of endocrine chemicals can affect our endocrine systems.

What Can We Do To Combat Plastic Pollution? 

We have to follow the five R Principle– refuse, reduce, reuse, recycle and rethink. Refuse and reduce the usage of plastics. Then reuse and recycle. But remember, recycling can cause harm as well, because that's again leaving the plastics in the system. So redesign or repurpose. Learn to live without plastic. It's not that plastic is absolutely necessary for humans. There are some critical plastics for medical purposes, but largely we can live with viable alternatives.

In humans, the evidence and research on the exact risks is still being assessed. So there are studies finding microplastics in blood and urine.

You Have Also Developed Treatment Technologies To Remove Microplastics And Other Contaminants From Waters. So Can You Shed Some Light On That?

We look at plastic as a three dimensional toxic. And so, it has a toxic chemical in it, and pathogens in it, and it's dangerous. We came up with the technology, and that's based on our extensive research on microplastics in various environmental matrices. Our technology is capable of not only removing microplastics from water, it also removes the chemicals. And it is able to perform this work in a small footprint. Our whole system can sit in a 40 feet container and it can treat the water continuously.

This Year's World Environment Day Theme Is ‘Beat Plastic Pollution’. What Can Different Stakeholders Bring To The Table In This Fight?

I think, mainly, policy changes are required. Don't allow unwanted plastic packaging, since it's totally unnecessary. Remove single use plastic like straws and carry-back coffee cups. The community should come up with a strategy to avoid plastics. In a country like India, there should be proper solid waste management facilities. You need to build a waste management capacity if you have to manage plastic. Use compostable plastics for replacing some of the necessary plastic. Then you can actually compost it along with your green waste and food waste.

So What Are The Biggest Challenges In The Fight Against Plastic Waste?

There's a strong push from the plastic industry. We have a long way to go because plastic is an established industry generating trillions of dollars and it's hard to defeat that. The momentum around it is growing and policy level changes are still emerging in various countries. Alternative products are also the key and they have to be readily available. So when you ban a product, you need to show the alternative.